基于时间域读出的大动态范围CMOS图像传感器

A High Dynamic Range CMOS Image Sensor Based on Time Domain

摘要:

设计了一款基于时间域读出的大动态范围CMOS图像传感器。传感器基于一种新型的结构，其可在时间域下探测高输入光强，在模拟域下探测低输入光强。设计在传统CTIA的基础上，新增了时间域测量电路，在不改变原有积分过程的同时可实现连续的大动态范围。基于0.35 μm，5 V-CMOS工艺进行了256×1线列CMOS图像传感器流片，光电二极管面积为22.5×22.5 μm2，并对器件的光电特性进行了后仿真验证。仿真测试结果表明，基于时间域读出的图像传感器可实现96 dB的大动态范围，且时间域和模拟域的两路输出信号可同步输出，功耗为7.98 mW。

Abstract:

A high dynamic range CMOS image sensor based on the time domain is presented. The sensor is based on a novel structure that can detect high input light intensity in the time domain and low input light intensity in the analog domain. A time domain measurement circuit is added to the traditional CTIA structure, which can achieve a continuous and large dynamic range without changing the original integration process. In this paper, a 256×1 linear CMOS image sensor based on CTIA pixel circuit was implemented in 0.35 μm, 5V-CMOS process, and the photoelectric response of the device was fully characterized and simulated. The simulation results show that the time domain CMOS image sensor can reach the dynamic range of 96 dB, and the two output signals of time domain and analog domain can be output synchronously. The power consumption is 7.98 mW.